Yarn tensioning device



3 Sheets-Sheet 1 Filed June 5, 1946 u v m Q N & 13: R Inventor is, I Raman c) Demms Attovn Dec. 28, 1948. R. DEWAS YARN TENSIONING DEVICE ,3Sheets-Shut 2 Filed June 5, 1946 w. D v! Yd e OK I ML w w Q MR Dec. 28,1948. R. DEWAS YARN TENSIONING DEVICE 3 Shocks-Sheet 3 Filed June 5,1945 l'nvcwt 0v R ay mend Dewas y duh-4K Patented Dec. 28, 1948 UNITEDSTATES PATENT OFFICE- YARN TENSIONING DEVICE Raymond Dewas, Amlens,France Application June 5, 1940, Serial No. 674,494 In France March 28,194.8

The invention relates to yarn tensioning devices which are used inparticular in textile machines and which comprise two circular memberscalled discs which are in contact with one another.

In one of these known types of tensioning devices, the discs which reston one another are provided with central holes or orifices through whichpasses the spindle of the tension device, which is fixed to a support byone of its ends; the diameter of the hole of the lower disc which restson a stationary ring being sufllcient to leave, between its circularedge and the spindle passing through it, an annular gap through whichcan be evacuated the material or the fluff which comes away from theyarn while it is passing through the device. The yarn passing betweenthe two discs comes into contact with the spindle which limits thelateral movement thereof, and is braked by the pressure exerted on it bythe upper disc.

In practice, it has been found that despite the more or less regularrotary movements imparted to the discs by the forward movement of theyarn, the material left by the yarn might succeed in obstructing thewhole or a part of the annular gap of the lower disc, therebysuppressing the contact between the discs, so that'the yarn was nolonger tensioned or was only insufficiently tensioned. r

Devices have already been proposed to obviat these drawbacks, but otherdifficulties have'then arisen.

The invention provides improvements in disc operated yarntensioningdevices, by means of which not only are the above-mentioned drawbackseffectively eliminated, but a number of advantages are obtained at thesame time which have made possible certain novel arrangements which intheir turn procure further advantages, as will be apparent hereinafter.

According to the invention, a first improvement made in the kind oftension devices referred to, wherein discs provided with a centralorifice rest one upon the other, consists in that the spindle 20 Chimp.(Cl. 242-) tral hole and not in the form of an annular opening which isthe cause of the accumulation, thereby enabling the diameter of saidhole to be reduced and, consequently, the size of the discs themselves,with the advantage which may accrue therefrom; a further result is thatsince the yarn, while it is passing through the device, no longer comesinto contact with the spindle of the tension device, it can movetransversely between the discs, whose surface it thus sweeps.

According to the invention, a second improvement, whose importance willbe brought forward hereafter, consists in providing means to limit theamplitude of the jumps of the upper disc,

which constitute a serious drawback in that they are breaking thecontact between both discs, which therefore, do no longer assure acontinuous and regular braking of the yarn.

According to the invention, another improvement consists in that aplurality of sets or pairs of discs may be arranged in alignment withone another, thereby enabling a novel kind of disc tension device to beobtained, through which the yarn passes in a straight line without anybend or any braking action other than that determined by the upperdiscs.

It is known to place consecutively a plurality of sets or pairs oftension discs through which the yarn passes successively, the spindlesof said tension devices being arranged approximately in an arc of acircle. But it has been found that the successive purchases or bendsthus formed have an undesirable action on the yarn which, in certaincases, may get untimely out of the discs.

According to the invention, other improvements further relate to theparticular shape of the lower and upper discs, to the arrangement ofmeans for threading the yarn at the inlet of the tension device, whichmeans are used, in particular, in the mascot the yarn being unwoundthrough a discontinuous, irregular or jerky take in, and

also to constructional details, as will become apv of discs, with a yarnthreading device,

Fig. 3 being a plan view thereof.

Fig. 4 is a view in side elevation of a modification of mounting of thedisc-carrier rings.

Figs. 5 and 6 are views in side elevation of two modifications ofmounting of the jump limiter.

Fig. '7 is a view in side elevation of a modification of construction ofthe jump limiter,

, Fig. 8 being a plan view thereof. I

Fig. 9 is a view in front elevation of'the yarn threading device ofwhich a side elevation is shown in Fig. 2 and a plan view in Fig. 3.

Fig. 10 is a view in front elevation of a similarly constructed doublethreading device for the case of two tension devices arranged'side byside,

Fig. 11 being a plan view thereof.

Fig. 12 shows a construction wherein the lower disc is rounded and theupper disc is flat.

In Fig. 1 are shown the component members of tension devices comprisingdiscs provided with a central orifice, which rest on one another, in

this case: a spindle I suspended by its head-- shaped end I on a fixedsupport 2, and alsoan upper disc 3 resting on a lower disc 4 whichitself rests on a fixed ring 5 mounted at the end of the arm 6 of asupport 1. The component members are however characterized,.according tothe invention, on the one hand by the fact that the spindle I, which nolonger has to act but as a centering and retaining means of the upperdisc 3 alone, ends above the level of the plane of contact of said discwith the lower disc 4, which plane coincides with that in which the yarn0 passes, and on the other hand by the fact that the discs 3 and 4 areof such cross-sectional shape'that the face of one of the discs,preferably the lower disc 4, which is intended to be in contact with theopposite disc, forms an annular flat portion 4, whereas the oppositedisc, preferably the upper disc 3, forms, on its contacting face, anannular projection 3' which is adapted to rest against the flat annularsurface 4', the run of the yarn a as it passes between these two annularsurfaces imparting to the discs a rotary movement which contributes tothe evacuation of the material detached from the yarn, through thecentral evacuation orifice 4", and said evacuation may be assisted by asweeping action which may be effected by the yarn owing to the factthat, since it is no longer stopped by the lower part of the spindle I,it can, then, move transversely. The. arrangement of the fiat and curvedportions of the discs 3 and i may bereversed, as shown in Fig. 12.

By the judicious arrangement and crossshaping of the discs 3 and 4, theextra thick portions of the yarn (bulges or knots) first come intocontact with the annular fiat portion 4' of the lower disc, then, bybearing thereon, lift the upper disc 3 with the least possible force andtherefore without appreciable increase of ten sion, such lifting beingall the more readily efl'ected as the angle between the discs isexceptionally small (18 in the embodiment shown). Owing to this fact,the upper disc is less liable to vibrate and does not jump so high,hence the getting out of contact are less frequent and of shorterduration and the strain on the yarn is less severe. Then, each extrathickness of the yarn gets out of contact with the upper disc 3 in thesame conditions of smoothness, then passes beside or over the evacuationhole l'j and again penetrates between the discs, then leaves them in thesame conditions.

As in the known tension devices, the weight of the upper disc 3 can beadjusted by means of 4 loading rings 8 testing on a ring 8, made of feltfor instance.

In order to limit and adjust the amplitude of the jumps of the upperdisc 3, a device is provided'which consists, in principle, as shown inFig. 1, of stop points which are located above the upper disc 3. oneither side of and at some distance from the spindle I, and againstwhich either the disc or its loading ring 3 abuts, said stop pointsbeing formed by the lower ends of two rods II supported by their upperends by a cross member I2, the whole arrangement being shaped like astaple, through the middle of which passes a screw-threaded rod I3, thelower end ofwhich penetrates into a smooth bore II provided in the headI and the spindle I.

To adjust the height of the stop ends of the arms I I of the staple, itis only necessary to screw or unscrew the rod I3 the desired amount forI formed by the end of springs, preferably located inside the rods;

By means of this l p limiter, the period of break of contact between thediscs is extremely short, so that the yarn is always kept taut, atleast, when the tension device comprises a plurality of sets of discs.Modifications may be made in the method of mounting the jump limiters.

For instance. the rod I3, instead of resting in the bore ll of thespindle I, may be screwed therein; or, as shown in Fig. 5, the crossmember I2 may be fixed to the end of the spindle I, the

locking being effected by the nut I5 pressing against the head I. Dragain, as shown in Fig. 6, the head I' may be surmounted by ascrewthreaded. rod I3 on which is screwed and locked by the nut I5, thecross member I2 'of the jump limiter with arms II.

Similarly, the jump limiter may, as shown in Figs. '7 and 8, merelycomprise two independent arms II placed in holes provided on thecrossmember 2 on each side of the hole intended to receive the "spindleI, and locked by nuts I5.

According to another improvement, the tension device comprises aplurality of sets of discs (preferably from three to seven) throughwhich the-yarn passes along a straight course. In the case in which thespindles I do not pass through the holes 4"-of the lower discs 4, theinserting of the yarn between the discs is effected on the side oppositethat which is to be occupied by the yarn when it comes in the operativeposition; in other words, the yarn is made to penetrate into the deviceon the side of. the discs opposite the stop fingers I! to whichreference will be made hereinafter. This yarn follows a straight course,thereby eliminating all additional bends and braking.

There is thus no objection to the first upper discs being loaded morethan the last ones, or, at any rate, as much as the last ones, by meansof the rings 3, thereby favouring the unkinking and thus contributing toenable the yarn to be given minimum .tension.

Such a construction of a tension device with a plurality of sets ofaligned discs comprises. as shown in Figs. 2 and 3, a common support,having a plurality of spindles I, which is formed by an upper crossmember- 2 of appropriate length ,to accommodate five heads I of spindlesI, for instance, and also a common support for a pluescape sideways,stop fingers I! may be provided which are located on the opposite sideto that on which the yarn is manually inserted between the discs, sothat the presence of said fingers does not in any way hinder orcomplicate this operation.

Said fingers are formed by vertically hanging rods I! which are passedthrough holes provided in the upper cross member 2 and which areretained by their head H in the same manner as the spindles l.

The presence of these fingers I! may enable the construction of thetension device with a plurality of sets of discs to be simplified, in asfar as the side cross member I supporting the stationary ring 5 can beeliminated. As shown in Fig. 4, the rods 11 are, in this case, locked onthe upper cross member 2 by nuts 18 and their lower ends are bent at ITand replace the arms 6 for supporting the stationary rings 5.

The supporting rings 5 may be provided, in all the embodiments, with apacking ID, of shock absorbing material which may be slippery or not.

In the case in which use is made of spindles I passing through the twodiscs in the hitherto usual manner, the yarn is engaged between thefingers and the discs and inserted between the latter by passing itabove the ends of the fingers.

A tension device having a plurality of sets of discs, involving theapplication of the improvements according to the invention, thereforedefinitely offers, as is apparent from the foregoing, numerousadvantages, inter alia that of providing, with yarns of various natures,a smooth and constant tension whatever be the speed of the yarn andwhether its drawor take in be continuous, discontinuous, irregular orjerky, thereby enabling the least possible tension to be applied, sothat the yarn undergoes the least possible strain and that in the caseof high twist, there is no risk of said twist being modified. Owing tothis fact, breakages of theyarn or defects in the product obtained areconsiderably lessened or eliminated. Finally, owing to its design, thetension device as a whole reduces to the strictest minimum the harmcaused by the fluff,

Another improvement according to the invention consists in the factthat, for the threading, a vertical plate i9 is provided which is' usedin combination with a second plate 20 arranged parallel with and spaceda short distance apart from same, in order to form a yarn threadingdevice by means of which threading by hand is readily and quicklyeffected.

ing nose 23 around which the yarn passes, and by following the upperinclined edge 24 of the recess,

said yarn is thus guided towards the centre of the plate to the end of aslit 25 extending the v recess 22.

The front plate 20, which is'cut of sheet metal,

has the appearance of a rectangle of which the left-hand side has alarge recess 26 for the inlet of the yarn fed from the bobbin as itunwinds, and the upper edge 210i which is rounded in order to guide thesaid yarn to the end of said recess 26 which terminates in the shape ofa slit 28. Said plate 20 is of sufficient size for there to be no dangerof the yarn catching as it unwinds from the bobbin (not shown).

These twoplates are arranged parallel. with one another and are securedtogether by means of a small intermediate plate 29 and the wholearrangement is assembled by means of screws 30, the thicknessof saidplate 29 determining the gap between the two plates l9 and 20, betweenwhich the yarn passes during the manual threading operation.

This operation is effected easily and, so to speak, instantly, byengaging the yarn in the recess 26 of the plate 20, then under the nose23 of the plate IS, the insertion into the recess 22 being facilitatedby slightly bending the nose 23, as

shown at 23', along a crease 23" (Figs. 9, 10 and 11).,

The yarn passing between the two plates, as shown at a. in Fig. 3, isthreaded between the two ends of the slits 25 and 28, the position ofwhich is equivalent to the formation of an eye (as shown in Fig. 9). Theyarn, after having then been inserted between the discs of the varioussets of the tension device, is passed through a U-shaped guide 3| 'whichis placed obliquely as shown in Fig. 3 and which closely holds the yarna in its straight position while not preventing the thicker portionsfrom passing, it being possible to turn the guide to enable the yarn tobe shifted sideways the desired amount between the pairs of discs, inwhich case, and in order to allow of a corresponding transverse movementof the yarn as soon as it enters the tension device, the adjustment ofthe respective position of the threading plates 19 and 20 may beeffected in such a manner that the ends of the slits 25 and 28 form theequivalent of an elongated eye.

In the case, for instance, of yarns having a high amount of twist, andif space is not available to enable a suificient number of sets of discsto be used, it may be advisable to form a bend at the inlet of the yarninto the tension device, so as to contribute to the unkinking of saidyarn. Such a bend is obtained by adjusting the respective position ofthe threading plates [9 and 20 in I 11, the threading plate I9 is soshaped as to have,

such a manner that the ends of the slits 25 and 28 give the portion ofyarn passing from one plate to the other the bend a" shown in dottedlines in Fig. 3.

When two tension devices are mounted side by side, the rear plate may beshaped similarly to the plate 19, so as to form, in combination with afront plate similarly shaped to the plate 20, a double threading device.

For this purpose, and as shown in Figs. 10 and symmetrically arranged,two noses 23 and two slits 25, whereas the large threading plate 20 isprovided with a single medial vertical slit which replaces the recess 26and the edges of which, to-

wards the centre of the plate, taper outwardly on each side and formrounded edges 2! which guide the yarns respectively td the left and toby being sup rpd ed on those of the slits 25. form devices therespective eyes of the two tension mounted side by side.

One of the plates I! or 2. may be vertically separated in two throughthe middlethereof. so as to enable, by shifting its parts, either theequivalent of elongated eyes to be formed, or the portions of the yarnpassing from one plate the other to be given the bent position as hereinbefore explained. a

It is also possible to obtain a double threading device by completingthe single threading device of Fig. 9 by its equivalent arrangedsymmetrically with respect to the edge of the plate 20 opposite therecess 26.

It is of course understood that, without deviatthe level. of the planeof contact of said upper; and lower discs.

2. A yarn tensioning device which comprises a V said fixed ring andhaving a central hole therein for the evacuation of the material orflufi which v becomes detached from the yarn as it passes being from thespirit of the invention, changes,

modifications and additions may be made, and also the use of equivalentmeans may be considered. For instance, the two first sets of discs maybe closer together than thenext ones, whose inter-axial spacing maygradually increase, this being in order to prevent the yarn, which isstill insufiiciently steady, from escaping from the first .set of discsand also in order to facilitate unkinking. Furthermore, the first set,for instance, may be staggered so that theyarn passes through the centrethereof, or nearer to its centre than.

in the subsequent sets. In addition, the lower discs 4 may be eliminatedand replaced by the supporting rings 5 themselves, the circular edge ofwhich is given a shape corresponding to that of the discs 4, the annularprojections 3 of the upper discs 3, in this case, beingto come intocontact with the smooth annular surfaces 4' of said supporting rings. r

It should be observed that the improvements relating to the absence of aspindle at the level of the plane of contact of the discs, to the shapeof the discs and to the device having multiple sets of discs, may alsobe applied to tension devices in which the loading rings are replaced bysprings, or act through the intermediary of springs.

On the other hand, and when the spindle ends above the level of theplane of contact of the discs, the upper disc need not have a centralorifice and may in that case be centred on the spindle, for instance bymeans of a bush or a projection loosely engaged on or in a correspondingpart of the spindle.

In the case in which two or more tension devices are mounted side byside, the upper cross members 2 may be connected together and optionallyto the side cross members 1, or to the common side cross'member 1, inany appropriate manner, and. in particular by the underneath,externally, and similarly the assembly may be supported, also inanyappropriate manner, by the threading plates, or other members.

Finally, as regards the stop fingers ll, thme may be fixedby their baseon a lower member.

I claim;-

l. A yarntensioning device which comprises a fixed support, a spindlesecured by one'of its ends to said support and projecting downwardlytherefrom, an upper disc rotatably mounted on tweensaid discs, thelength of said spindle being limited so that itslower end is locatedabove the level of the plane of contact of said upper and lower discs,and means for limiting the amplitude of the vertical'movement of theupper disc. A

3. A yarn tensioning device which comprises a fixed support, a spindlesecured by one of its endsto said support andprojectlng downwardlytherefrom, an upper disc rotatably mounted on said spindle, afixedconcentric ring located besaid spindle, a fixed concentric ring locatedbelow and spaced apart from said upper disc, 9. lower disc adapted torest on the upper face of said fixed ring and having a centralholetherein for the evacuation of the material or fluff which becomesdetached from the yarn as. it passes between said discs, the length ofsaid spindle being limited so that its lower end is located above thelevel of the plane of contact ofsaid upper and lower discs, and meansfor limiting the amplitude of the vertical movement of the upper disc,said means consisting in at least a stop located above said upper disc.

4. A yarn tensioning device which comprises a fixed support, a spindlesecured by one of its ends to said support and projecting downwardlytherefrom, an upper disc rotatably mounted on said spindle, a fixedconcentric ring located below and spaced apart from said upper disc, a

lower disc adapted to rest on the upper face of said fixed ring andhaving a central hole therein for the evacuation of the'material orflufi which becomes detached from the yarn as it passes between saiddiscs, the length of said spindle being limited so that its lower end islocated above the level of the plane of contact of said upper and lowerdiscs, and means for limiting the amplitude of the vertical movement ofthe upper disc, said means consisting in at least a stop located abovesaid upper disc, on either side of and at some distance from saidspindle.

5. A yarn tensioning device which comprises a fixed support, a spindlesecured by one of its ends to said support and projecting downwardlytherefrom, an upper disc rotatably mounted on said spindle, a fixedconcentric ring located below and spaced apart from said upper disc, a

lower disc adapted to rest on the upper face of said fixed ring andhaving a central hole therein for the evacuation of the fluff ormaterialwhich becomes detached from the yarn as it passes between saiddiscs, the length of said spindle being limited so that its lower end islocated above the level of the plane of contact of said upper and end ofsaid downwardly projecting rods acting as stops for limiting theamplitude of the vertical movement of said upper disc.

6. A yarn tensioning device which comprises a fixed support, a spindlesecured by one of its ends to said support and projecting downwardlytherefrom, an upper disc rotatably mounted on said spindle, a fixedconcentric ring located below and spaced apart from said upper disc, alower disc adapted to rest on the upper face of said fixed ring andhaving a central hole therein for the evacuation of the material orfluff which becomes detached from the yarn as it passes between saiddiscs, the length of'said spindle being limited so that its lower end islocated above the level of the plane of contact of said upper and lowerdiscs, and at least two independent downwardly projecting rods securedto said fixed support on either side of said spindle, the lower ends ofsaid rods acting as stops for limiting the amplitude of the verticalmovement of' said upper disc.

'7. A yarn tensioning device which comprises a fixed support, a spindlesecured by one of its ends to said support and projecting downwardlytherefrom, an upper disc rotatably mounted on said spindle, a fixedconcentric ring located below and spaced apart from said upper disc, alower disc adapted to rest on the upper face of said fixed ring andhavinga central hole therein for the evacuation of the material or fiufiwhich becomes detached from the yarn as it passes between said discs,the length of said spindle being limited so that its lower end islocated above the level of the plane of contact of said upper and lowerdiscs, downwardly projecting rods acting as stops for limiting theamplitude of the vertical movement of said upper disc, and resilientmeans at the lower end of said downwardly projecting rods.

8. A yarn tensioning device which comprises a fixed support, a spindlesecured by one of its ends to said support and project ng downwardlytherefrom, an upper disc rotatably mounted on said spindle, a fixedconcentric ring located below and spaced apart from said upper disc, alower disc adapted to rest on the upper face of said fixed ring andhaving a central hole therein for the evacuation of the material orfluff which becomes detached-from the yarn as it passes between saiddiscs, the length of said spindle being limited so that its lower end islocated above the level of the plane of contact of said upper and lowerdiscs, the upper end of said spindle having a smooth bore therein, and arod having an upper screw threaded portion, the smooth end of said rodbeing inserted in said bore, a transverse member having a central tappedhole therein adapted to screw on said rod and to be locked thereon by anut, a downwardly projecting rod secured to each end of said transversemember and forming therewith a staple-shaped assembly, and resilientmeans at the lower end of said downwardly projecting rods for limitingthe amplitude of the vertical movement of said upper disc.

9. A yarn tensioning device which comprises a fixed support, a spindlesecured by one of its ends to said support and projecting downwardlytherefrom. an upper disc rotatably mounted on said spindle, a fixedconcentric ring located below and spaced apart from said upper disc, alower disc adapted to rest on the upper face of said fixed ring andhaving a central hole therein for the evacuation of the material orfluff which 10 becomes detached from the yarn as it passes between saiddiscs, the length of said spindle being limited so that its lower end islocated above the level of the plane of contact of said upper and lowerdiscs, at least two independent downwardly extending rods secured tosaid fixed support on either side of said spindle, and resilient meansat the lower end of said downwardly extending rods for limiting theamplitude of thevertical movement of said upper disc.

10. A yarn tensioning device which comprises a fixed support, a spindlesecured by one of its ends to said support and extending downwardlytherefrom, an upper disc rotatably mounted on said spindle, a fixedconcentric ring located below and spaced apart from said upper disc, alower disc adapted to rest on the upper face of said fixed ring andhaving a central hole therein for the evacuation of the material orfluff which becomes detached from the yarn as it passes between saiddiscs, said discs being so shaped that face of said lower disc which isadapted to come into contact with the upper disc has a fiat annularsurface thereon, whereas the face of the upper disc forms an annularprojection adapted to come into contact with the fiat annular surface ofthe lower disc.

11. A yarn tensioning device which comprises a fixed support, a spindlesecured by one of its ends to said support, an upper disc rotatablymounted on said spindle, a fixed concentric ring located below andspaced apart from said upper disc, a lower disc adapted 'to rest on theupper face of said fixed ring and having a central hole therein for theevacuation of the material or fluff which becomes detached from the yarnas it passes between said discs, said discs being so shaped that theface of said lower disc which is adapted to come into contact with theupper disc has an annular projection thereon, whereas the face of theupper disc forms a flat annular surface adapted to come into contactwith the annular projection of the lower disc.

12. A yarn tensioning system, which comprises a plurality of tensioningdevices arranged in a row in mutual spacedrelation, a spindle secured byone of its ends for each of said tensioning devices and extendingdownwardly therefrom, an upper disc rotatably mounted on each of saidspindles, a fixed concentric ring located below and spaced apart fromeach of said upper discs, a lower disc adapted to rest on the upper faceof each of said fixed rings and having a central hole therein for theevacuation of the material or fluff which becomes detached from the yarnas it passes between said discs, the row of tensioning devices being soarranged that the yarn passing successively between the discs of eachtensioning device follows a straight course.

13. Yarn tensioning system according to claim 12, wherein saidtensioning devices are arranged in evenly spaced relation.

14. Yarn tensioning system according to claim 12, wherein saidtensioning devices are arranged in progressively increasing spacedrelation.

15. A yarn tensioning system, which comprises a plurality of tensioningdevices arranged in a row in mutual spaced relation, 9. spindle securedby one of its ends for each of said tensioning devices and extendingdownwardly therefrom, an upper disc rotatably mounted on each of saidspindles, a fixed concentric ring located below and spaced apart fromeach of said upper discs, a lower disc adapted to rest on the upper faceof each of said fixed ringsand having a central 11 hole thereinfor theevacuation of the material or fiufi which becomes detached from the yarnas it passes between the discs, the length of said spindles beinglimited so that their lower end is located above the level of the planeof contact of said upper and lower discs, the row of tension devicesbeing so arranged that the yarn passing successively between the discsof each tension device follows a straight course, and so, is enabled tomove laterally in the system.

16. A yarn tensioning system, which comprises a plurality of tensioningdevices arranged in a row in mutual spaced relation, a spindle securedby one of its ends for each of said tensioning devices, and extendingdownwardly therefrom, an upper disc rotatably mounted on each of saidspindles, a fixed concentric ring located below and spaced apart fromeach of said' upper discs, a lower disc adapted to rest on the upperface of each of said fixed rings and having a central hole therein forthe evacuation of the material or fluff which becomes detached from theyarn as it passes between the discs, the length of said spindles beinglimited so that theirlower end is located above the level of the planeof contact of said upper and'lower discs, the row of tension devicesbeing so arranged that the yarn passing successively between the discsof each tension device follows a straight course, and is enabled to movelaterally in the system, and

means for limiting the lateral movement of said yarn.

17. A yarn tensioning system which comprises a support formed by anupper transverse member and a lower lateral transverse member, aplurality of downwardly extending spindles secured by one of their endsto said upper transverse member and arranged in a row in mutual spacedrelation, an .upper disc rotatably mounted on each of said spindles, aconcentric fixed ring secured to said lower transverse member andlocated below and spaced apart from each of said upper discs, a lowerdisc adapted to rest on the upper face of each of said fixed rings andhaving a central hole therein for the evacuation of the material orfiufi which becomes detached from the yarn as it passes between saiddiscs, the length of said spindles being limited so that their lower endis located above the level of the plane of contact of said upper andlower discs, the row of tension devices being so arranged that the yarnpassing successively between the discs of each tension device follows astraight course.

18. A yarn tensioning system, which comprises a support formed by anupper transverse member and a lower lateral transverse member, aplurality of downwardly extending spindles secured by one of their endsto said upper transverse member and arranged in a row in mutual spacedrelation, an upper disc rotatably mounted on each of said spindles, aconcentric fixed ring secured to said lower transverse member andlocated below and spaced apart from each of said up per discs, a lowerdisc adapted to rest on the upper face of each of said fixed rings andhaving a central hole therein for the evacuation of the material orfluff which becomes detached from the yarn as it passes between thdiscs, the length of said spindles being limited so that their lower endis located above the level of the plane-of contact of said upper andlower discs, the row of tension devices being so arranged that the yarnpassing successively between the discs of each tension device follows astraight course, and fingers secured by their upper end to saiduppertransverse member and extending downwardly therefrom between eachsuccessive tension device, thereby preventing the yarn from leaving thediscs sideways thereof.

19. A yarn tensioning system, which comprises a support, a plurality ofdownwardly extending spindles secured by one of their ends to saidsupport and arranged in a row in mutual spaced relation, an upper discrotatably mounted on each of said spindles, a plurality of downwardlyextending fingers secured by their upper end to said support, saidfingers being bent substantially at right angles intermediate theirends, a concentric fixed ring secured to the horizontal portion of eachof said fingers and located below and spaced apart from each of saidupper discs, 9. lower disc adapted to rest on the upper face of each ofsaid fixed rings and having a central hole 'therein for the evacuationof the material or fiuif which becomes detached from the yarn as itpasses between said discs, the length of said spindles being limited sothat their lower end is located above the level of the plane of contactof said upper and lower discs, the row of tension devices being soarranged that the yarn passing successively between the discs of eachtension device follows a straight course, the substantially verticalportion of said fingers extending between each successive tension deviceand preventing the yarn from leaving the discs sideways thereof.

20. 'A yarn tensioning system according to claim 18, wherein meansassociated with the upper transverse member are provided for guiding theyarn as it comes out of the discs of the last tensioning device.

RAYMOND DEWAS.

REFERENCES CITED The following references are of record in the file ofthis patent:

UNITED STATES PATENTS Swanson Dec. 16, 1947

